The proposed research is designed to develop therapeutic methods to reduce excessive splenic function while retaining some immune protective function of the spleen in experimental hypersplenism. The treatments to be evaluated included splenic artery ligation, splenic artery embolization and splenectomy. In the normal rat and the rat model of methylcellulose induced hypersplenism, hematologic and immunologic parameters (primary and secondary immune response) will be followed before and after treatment.